Royal wedding protesters take Met police to high court

Force accused of operating unlawful policy of 'pre-emptive' arrests in case that activists say has implications on policing this summer

Twenty individuals arrested or subjected to police searches during the royal wedding on 29 April 2011 are challenging the legality of the policing of the event in London last year. Photograph: Rebecca Naden/PA

Human rights activists say the case has major implications for the policing of other major events this summer, including the Queen's diamond jubilee and the Olympics.

Lord Justice Richards, who is hearing the judicial review application in London with Mr Justice Openshaw, indicated that the court's ruling was likely to come too late to influence the jubilee.

Karon Monaghan QC, appearing for 15 applicants, said her clients were all pre-emptively arrested on Friday 29 April 2011, when Prince William married Kate Middleton.

They were arrested in four separate locations in central London, on suspicion of being about to commit breaches of the peace.

Monaghan said those she represented were held at police stations – and the signal for their release from custody was "the balcony kiss" of the royal couple.

The case related to "the most important of constitutional rights, namely the rights to free expression and to protest, both of which are elemental to a properly functioning democracy", Monaghan told the court.

In policing the royal wedding, the Met "operated a policy of equating intention to protest, whether perceived or actual, with intention to cause unlawful disruption".

The commissioner had "adopted an impermissibly low threshold of tolerance for public protest, resulting in the unlawful arrests of those who were viewed by officers as being likely to express anti-monarchist views".

The threshold was so low as to amount to the suppression of anti-monarchist sentiment.

It was not being argued that the right to protest was absolute, "it is not but it is recognised as a preciously guarded freedom", Monaghan said.